This invention relates to a nosepiece for autofeed screwdrivers and, more particularly, to a nosepiece with at least one hook-like channelway to catch the tips of misaligned screws and assist in keeping such screws within the nosepiece.
Autofeed screwdrivers are known such as those taught in the present inventor""s U.S. Pat. No. 5,934,162, issued Aug. 10, 1999 in which successive screws held in a screwstrip such as that taught in the present inventor""s U.S. Pat. No. 5,699,704, issued Dec. 23, 1997 are advanced while held in the screwstrip into a guide tube with their heads axially aligned with a reciprocating driver shaft for engagement by the driver shaft and driving out of the screwstrip and into a workpiece. The nosepiece typically has a slotway-like screw access opening in one radial side through which the screw is radially advanced into the guideway. The present inventor has appreciated that in driving large numbers of screws, there is probability of a screw being driven adopting a configuration in which, while the head is engaged by the driver shaft, the axis of the screw is significantly out of axial alignment with the driver shaft. With such a xe2x80x9crenegadexe2x80x9d screw, the tip of the screw can extend out of the screw access opening and either extend into the workpiece at an unacceptable angle and/or jam the screwdriver mechanism. When such a renegade screw configuration arises, a user preferably stops driving the screw and removes it, however, in any event, causing difficulties in operation and taking up time.
To at least partially overcome these disadvantages of previously known devices, the present invention provides a nosepiece with a screw retaining groove along a screw guideway near the screw access opening to assist in retaining screws which would otherwise come to have their tips extend out of the screw access opening.
An aspect of the present invention is to provide an improved nosepiece for autofeed screwdrivers which assists in preventing screws being driven from having their tips extend out of a screw access opening to a channelway from which screws are being driven.
In one aspect, the present invention provides a screwdriver nosepiece comprising an open-sided tubular member having a wall circumferentially about a central passageway extending therethrough and open at both ends,
the passageway including:
a cylindrical guideway extending about an axis and adapted to receive a screw coaxially therein for rotation and driving of the screw axially through the guideway by a driver shaft, and
a screw catch groove disposed axially along the guideway cut into the wall extending radially outwardly from the guideway and opening radially inwardly into the guideway to define a catch surface on the wall within the catch groove,
a slotway axially along the guideway extending radially outwardly from the guideway entirely through the wall and of sufficient circumferential extent to permit entry of a screw radially into the guideway while maintaining the screw substantially parallel the axis,
the catch groove located on the wall circumferentially proximate the slotway with the catch surface directed away from the slotway.
In another aspect, the present invention provides a screwdriver nosepiece having a guideway therethrough about an axis adapted to receive a screw and assist in guiding the screw coaxially therein while the screw is driven axially from the guideway by a coaxially slidable rotating driver shaft,
a slotway opening radially into the guideway permitting entry of a screw radially into the guideway with the screw substantially parallel the axis,
the guideway and slotway defined by a wall extending circumferentially about the guideway from a first end of the wall at a first side of the slotway to a second end of the wall at a second side of the slotway,
the first end of the wall forming a first hook member located radially outwardly from the guideway and presenting a bight radially outwardly from the guideway, extending axially along the guideway and opening radially into the guideway.
In another aspect, the present invention provides A screwdriver having a nosepiece having a nose portion with a cylindrical guideway passing therethrough about an axis,
a rotating driver shaft coaxially slidable in the guideway,
the guideway adapted to receive a screw therein to be driven axially from the guideway by the driver shaft,
the nose portion having a wall extending at least partially circumferentially about the guideway and axially thereof with an inner wall surface having part-cylindrical portions of a constant diameter defining at least in part a cylindrical periphery of the guideway,
an axially extending slotway opening radially outwardly from the guideway through the wall, the slotway having two sides circumferentially spaced about the axis, each with an inner wall surface,
a part-cylindrical portion of the inner wall surface on a first side of the slotway merging into portions of the inner wall surface of the slotway on that first side,
a first screw tip catching catch trough extending axially along the inner wall surface about the guideway near a first side of the slotway extending radially outwardly from the guideway and opening radially inwardly into the guideway, the catch trough adapted, when engaged by a tip of a screw whose head is in the guideway, to prevent the tip from sliding circumferentially toward the slotway.
Further aspects of the invention will become apparent upon review of the following detailed description.